Horseshoe-calk.



No. 700,057.. a Patented May l3, I902.

E.VF LA CLAIR. HOBSESHOE CALK.

(Application filed Feb. 15, I901.)

(N0 Mode-l.)

a said improvement.

UNITED STATES PATENT OFFIcE.

EDMUNDF. LA CLAIR, OF AVON, CONNECTICUT.

HORSESHOE-CALK.

SPECIFICATION-forming part of Letters Patent No. 700,057, dated May 13, 1902'. I

Application filed February 15 1901. $erial No. 47,452. (No model.)

To aZZ whom it may concern.-

Be it known that I, EDMUND F. LA CLAIR, a citizen of the United States of America, residing at Avon, (post-office address at Co1lins- Ville, Connecticut,) in the town of Hartford and State of Connecticut,have invented a certain new and useful Improvement in Horseshoe-Calks,of which the following is a description, reference being had to the accompanying drawings,- where Figure 1 is a side view of a calk embodying Fig. 2 is a face view of the same calk.- Fig. 3 is a view of the same calk in vertical section on the plane as' 00'. Fig. 4 is a diagrammatic View illustrating the advantages resulting from the use of this invention.

The object of the improvement is the production of a horshoe-calk having features of novelty and advantage.-

This horseshoe-calk has a screw-threaded pintle a, by which to screw it into the'shoe- I inent makes the hold of the shoe upon the the stratum of iron is of a sharper taper than pintle and calk more securethan if the pintle and hole were both regularly cylindrical.

The calk is wedge-shaped, asshown in the drawings. One longitudinal stratum of the calk (for instance, that half to the left of the dotted line y y) is of steel and the other por tion or stratum is of iron, the two being united by welding or otherwise.

The calk is rectangular in shape at the base that it may be seized by a wrench for screwing it intoa shoe and unscrewing it therefrom. It is wedge-shaped in order tohave what is practically an edge. 'It is i made of iron and steel in two longitudinal, strata in order that the iron may wear away faster than the steel, and thereby keep the calk always sharp. It keeps the calk sharp in a peculiar fashion, for after the iron begins to wear both sides of the point are of steel and the face of the face, which is Wholly of steel, a form which works in practice and endures well.

The enormous demand for so-called self sharpening calks has led to many efiorts to produce one of steel and iron so arranged that as the metals wear away the remaining or projecting portion of the calk will be pointed, and the prevailing idea for many years has been that a wedge-shaped calk having an iron body with a'steel center would produce this desideratum. I have discovered by experiment, however, that it is impossible to harden a steel calk satisfactorily while it is surrounded by iron, and it is quite expensive to make an iron calk bored with a hole and then insert the steel plug or core. Even so, a calk thus constructed does not maintain its pointed 'shape as it wears.

In the construction of my improved calk herein described the stock is made in long bars, half steel and half iron, and these bars are then cut into pieces, forged into shape, and finally threaded. Afterward the calk is hardened. The iron will not harden, but the steel will, and that part of the steel which is next adjacent to the divisional line between the two will not harden as much as the other part of the steel, the reason being that no piece of steel is as hard anywhere as at or near its exposed surface. The result is that when the finished article wears it wears on the dotted lines in Fig. 4, the iron wearing 0E very easily, the steel where it is softer wearingoff rather easily, but not so easily as the iron, and the remaining portion of the steel wearing off more slowly. A calk is thus produced which is positively self-sharpening.

I claim as my improvement- 'A downwardly-tapering detachable liorse= shoe-calk having one longitudinal-portion of iron, and the other portionof steel, the steel being harder in its exposed parts remote from the iron.

EDMUND F. LA CLAIR.

Witnesses:

E. M. YEOMANS,

V LUETGARD A. MORLA; 

